Mono Lake rises in wet summers and years and falls in dry summers and years. It also tends to rise in the winter and spring, and declines in autumn.

How is Mono Lake's level measured?

The lake level gage is a staff gage located near Old Marina that is demarcated in tenths and hundredths of a foot. DWP surveys the elevation of the gage each time it puts one in. The Mono Lake Committee and the Mono Lake Tufa State Reserve try to read it at least once a month. DWP reads it approximately weekly.

Current gage:

5/23/14 gage 1S installed with a zero elevation of 6377.79 USGS.

9/23/09 gage 1R adjusted and surveyed about a mile east of Old Marina and all other gages at this location removed. Zero elevation is 6379.997 feet above sea level USGS. Underwater as of July 2011 and on dry land as of July 2014.

Old Marina Gage 2A installed March 14, 2007, resurveyed 8/1/07, zero elevation 6382.06 USGS. Mono Lake dropped below zero on this gage in August 2009 and the staff plate was removed in September. In 2011 the staff plate was reinstalled and the new zero elevation was 6382.059.

"Target" level:
6391'Mono Lake is currently in a long-term transition to higher lake levels. 6391' is a target level that triggers changes in water export rules. Models indicate it could take over 20 years to reach this level. If it is not achieved by 2020, the Water Board will hold a hearing to consider the condition of Mono Lake and determine if further license revisions are appropriate.

Management level: 6392'Once the 6391' target is achieved, the water export rules change in order to maintain a long-term average lake elevation—or "management level"—of 6392'. It is anticipated that this level will maintain a healthy lake ecosystem and provide protection for the basin's resources such as the quality of the air.